(1) Field of the Invention
The present invention relates to an artificial tooth having a reference point that facilitates grinding, a method for determining a grinding portion of artificial tooth, and a method for manufacturing a denture with artificial teeth.
(2) Description of Related Art
Heretofore, after making dentures, the dentures have been adjusted by rubbing the maxillary denture and the mandibular denture against each other in a process called grinding. The grinding has been performed as a process including two steps of: adjusting the dentures by attaching the dentures on an articulator and grinding little by little with a grinder while ascertaining contact portions between the maxillary denture and the mandibular denture; and then adjusting the dentures by applying a paste material containing abrasive particles to the occlusal surface and rubbing the maxillary denture and the mandibular denture against each other. Depending on the conditions of the dentures, the adjustment of the dentures has been performed using only one of these steps in some cases. However, there is no way to know whether portions to be ground are correctly determined. Thus, it has been difficult to determine whether the grinding is performed correctly.
Furthermore, it is necessary to perform grinding or an occlusal adjustment of the prepared prosthesis when the antagonist is a natural tooth. The occlusal adjustment of the prosthesis is adjusted by grinding the prosthesis little by little with a grinder to perform polish finishing while ascertaining contact portions of the prosthesis. However, there is also no way to know whether the portions to be occlusal adjusted was correctly determined, and it was also difficult to determine whether the occlusal adjustment was performed correctly.
Furthermore, dental students are educated about grinding and occlusal adjustment of prostheses at their universities. Although the teachers of each university carefully teach the grinding sites of prostheses and the occlusal adjustment thereof, much time has been required to improve the skills of the students because of difficulty in these areas. Students have a narrow window of opportunity to learn from one another a method of clearly recognizing a difference between the properly performed condition of grinding or occlusal adjustment, and the improperly performed condition in an objective manner. In addition, it is difficult for the students to know the degree to which they have acquired the skills. The students have to ask a dentistry instructor to confirm whether the grinding and occlusal adjustment steps are performed properly. There has been no way to know how to personally determine the grinding and occlusal adjustment in an objective manner.
JP-A-05-95968 discloses a dental model processing apparatus which is capable of drilling to insert a pin on a bottom surface of a dental model on an upper work table, and also capable of grinding inner and outer profile surfaces of the dental model on a lower work table. This processing apparatus is not intended for grinding an occlusal surface. Thus, it cannot be used for grinding the occlusal surface because of its structure.
JP-A-10-225469 discloses a method of arranging artificial teeth in which ground artificial tooth are used. However, a grinding adjustment is required because a small distortion or the like occurs in the production of a denture base. Thus, JP-A-10-225469 is not relevant to the present invention.
JP-A-2000-316876 discloses a drive apparatus for artificial-tooth grinding that intends to enhance an efficiency of grinding artificial tooth on an articulator. In the drive apparatus, a transducer linked to an oscillator circuit is installed as a driving unit for grinding on an articulator for grinding and occlusal adjustment of artificial tooth. However, the drive apparatus performs the grinding by rubbing the maxillary denture and the mandibular denture against each other.
Thus, it is difficult to perform arbitrary adjustment.